This section provides background information related to the present disclosure which is not necessarily prior art.
Unlike traditional open surgery where tasks such as ligating vessels or tying off ductal structures are performed with ease, these same tasks in laparoscopic surgery are much more difficult. In traditional open surgery, these tasks are performed by the surgeon using varied types of suture material and manually passing the suture around the structure and then manually tightening to occlusion using multiple knots. Alternatively, the surgeon may consider clamping the structure first on either side, dividing it, and then manually tying each side of the vessel or ductal structure.
Varied mechanisms exist for the ligation of vascular or ductal structures in laparoscopic surgery. The first includes metallic or plastic clip mechanisms. These can be somewhat secure, but are limited by size and length of intended structure. Metallic clip mechanism have the advantage of multiple clips per device, but are generally limited to structures of one centimeter in diameter and have a tendency to slide on vascular tissue. Plastic clip systems can come in slightly larger sizes, but are typically single-load devices and have a tendency to misalign. They tend to be slightly more secure than metallic.
The second type of device commonly available is a linear-stapling device that uses multiple rows of small staples to secure and divide tissue. The advantages of these devices are the large amount of tissue that can be ligated as well as the ability to divide all types of tissues. The staples are considered very secure. However, the devices currently are quite bulky and have a large end effector that can require a larger cannula as well. The end effector size requires adequate space to encompass the vessel or ductal structure which can, in certain areas of the body, be very difficult due to the close proximity of abdominal cavity or of other vessels.
Finally, the most recent type of sealant devices utilized are varied types of energy including ultrasonic or bipolar electricity to denature proteins to seal structures. These devices can be very rapid in use and allow for continuous usage, they are limited in the size of vessel and type of tissue that can be ligated with adequate seal. Currently recommendations are for structures less than approximately 7 mm.
Mechanical devices designed to place a preformed loop around vessel structures do exist. However these types of devices are limited by the need for an open end of the intended tissue to be available to place the suture around.
Some automated devices that have been created for suturing tissue that may be utilized for the purpose of ligating a vascular structure. U.S. Pat. No. 5,417,700 describes a device specific to using a needle to penetrate tissue for the purpose of approximating tissue and then utilizes energy to seal the suture. This device's primary intention is for the approximation of tissue and is limited in its size of vasculature ligation as well as the presence of a needle to advance the suture material which can penetrate vasculature structures causing damage. The device additionally describes the ability to utilize heat to fuse suture. However, the use of an endplate to overlap the suture can result in an unwanted space in the loop of suture resulting in incomplete occlusion.
In other minimally invasive surgical procedures, small incisions are made in the abdomen and specialized instruments are used through varied access points to accomplish the performance of a surgical procedure. Unlike traditional open surgery involving a large incision, technical aspects such as suturing and tying are much more difficult.
In traditional open surgery, a commonly-used device is suture on a curved needle used for suturing and subsequently manually tying. In contrast, the use of a curved needle in laparoscopic surgery is especially difficult and rarely performed in the same manner, or speed as in open surgery. Additionally, certain angulations that occur during laparoscopic surgery, such as sewing against the anterior abdominal wall are even more difficult.
A common procedure that requires sewing against the abdominal wall is the performance of ventral or incisional abdominal wall hernia repairs. During open surgery, a synthetic or biological mesh is sewn with suture on a curved needle onto the abdominal wall to affix the mesh to the abdominal wall. The depth of penetration is critical to obtaining adequate layers of the abdominal wall. In laparoscopic surgery due to the severe technical difficulty of suturing the abdominal wall, the technique of mesh fixation has had to be altered to accommodate the inability for most surgeons to replicate the technique used in open surgery.
Typically during laparoscopic ventral hernia repair a flat piece of synthetic mesh is rolled and inserted through small opening into the insufflated abdominal cavity. There it is unrolled and affixed to the abdominal wall using a tacking device with or without the addition of sutures. The tacking devices are varied in their delivery system but fall into two categories, non-absorbable metal tacks and absorbable polymer tacks. While efficient in its use the tacks are limited in utility. Non-absorbable tacks are titanium and expose the bowel to bare metal which has shown the risk of injury to the intestine. Absorbable tacks are made from polymers and therefore are limited in their gripping strength and depth of penetration.
As solely tacking the mesh to the abdominal wall may not provide adequate apposition to limit the mesh migration, the same types of sutures used in open surgery are typically used as adjunct. However in laparoscopic surgery the sutures are passed through the abdominal wall from an external source into the abdomen then pulled back out and tied down, so called trans-fascial suturing. While very secure, this technique is difficult and time consuming and exposes the patient to the risk of transmigration of bacteria from the skin surface. The ideal solution would be to replicate the same technique used in open surgery of utilizing a curved needle and suture during laparoscopic surgery.